Water-insoluble monoazo dyestuffs



United States Patent WATER-INSOLUBLE MONOAZO DYESTUFFS Gerhard Wolfriim, Opladen, and Rolf Putter, Dusseldorf,

Germany, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Aug. 11,1958, Ser. No. 754,162

Claims priority, application Germany Aug. 21, 1957 6 Claims. (Cl. 260-163) The present invention relates to new monoazo dyestuffs; more particularly it relates to water-insoluble monoazo dyestufis of the formula OgS-CH2 In this formula R means hydrogen, a lower alkyl, aryl, carboxylic acid ester or lower alkylene carboxylic acid ester group, R stands for the radical of a diazo compound, and R and R are free of sulfonic acid and carboxylic acid groups.

The new monoazo dyestuffs are obtainable by coupling diazo compounds with l-(tetrahydrothiophene-1-dioxide- [3'] )-5-pyrazolones of the following formula O1S-CHB wherein R denotes hydrogen, a lower alkyl, aryl, carboxylic acid ester or alkylene carboxylic acid ester group, and by selecting the components so that they are free from sulfonic acid and carboxylic' acid groups.

For'the production of the new dyestuffs there are used as diazo components, aromatic or heterocyclic amines which may for example by substituted by alkyl, aryl, aralkyl, CO-alkyl, CO-aryl, O-alkyl or -Oa ryl groups, by halogen, -NO --CN, -CF SO N --SO -alkyl, -SO -aryl, SO -O-aryl, -NH-COalkyl, -NH-COaryl, CONI-I --a-lkyl or -CONH--aryl groups, but which are free from sulfonic acid or carboxylic acid groups. The radical R in the azo component may be substituted in' the same way if it represents an aryl radical.

The 1- (tetrahydrothiophene-l '-dioxide- [3 )-5-pyrazolones used as azo components are obtainable according to known methods by reacting B-keto-acid esters or 13-keto-acid amides such as inter alia acetoacetic acid ester, acetoacetic acid amide, oxalacetic acid ester, benzoylacetic acid ester or acetone-dicarboxylic acid ester, with 3-hydrazino-tetrahydrothiophene-l-dioxide obtained by adding hydrazine on butadiene sulfon.

The azo dyestuiis obtainable according to the present process are suitable for the dyeing of acetate rayon, polyamide fibres and especially of materials of polyethylene terephthalate in the form of filaments, ribbons, foils and the like.

The dyestuffs are very finely dispersed with the aid of dispersing and/or Wetting agents and dyed on the aforesaid materials, with the addition of auxiliaries such as carriers or other substances having a similar action if 2,957,863 Patented Oct. 25, 1960 desired. The dyeings on aromatic polyester fibres are distinguished by a good to very good fastness to wet processing, a good fastness to sublimation and, in general, bya good to very good fastness to light.

The following examples are given for the purpose of illustrating the invention without, however, limiting it.

thereto, the parts by weight and the parts by volume standing in the ratio of grams to millilitres.

Example I 9.3 parts by weight of aminobenzene are dissolved in 70 parts by volume of water and 60 parts by weight of 4n hydrochloric acid and diazotised at 0-5 C. with 70 parts by weight of a 10 percent sodium nitrite solution. The diazonium salt solution thus obtained is run at 5-10 C. into a suspension of 22.7 parts by weight of 1-(tetrahydrothiophene-l'-dioxide- [3'] )-3-methyl-pyrazo- I is ground in a ball mill for 24 hours.

subsequently dried in vacuo and the dyestufi thus obtained is'thoroughly kneaded for 2 to 3 hours with 22.5 parts by:

lone-(5) (M.P. 214'216 C.) in 70 parts by volume of weight of sulphite waste liquor and a little water. The product is then dried at 4060 C. and the residue ground.

1 part by weight of the dyestufr powder thus obtained is stirred in 2000 parts by volume of hot water containing 8-10 parts by weight of .a carrier such as benzoic acid and adjusted with sulphuric acid to a pH value of, about 4.5. A very fine dyestufi dispersion is thus. obtained into which 50 parts by weight of aromatic:

polyester fibres are introduced at 40-60 C. The dyebath is heated to the boil within 20-30 minutes and kept at this temperature for 11 /2 hours. The dyed material is subsequently thoroughly rinsed with water and then dried. A yellow dyeing is obtained having a very good fastness to Wet processing and a good fastness to subliming. A dyeing of a similar shade is obtained on acetate rayon according to the dyeing instructions com--' monly used for this type of fibre.

By the term aromatic polyesters or polyethylene terephthalate fibres there is understood the highly polymeric esters obtainable by heating glycols with terephthalic acid or with an ester forming derivative thereof,

for example, an aliphatic or cycloaliphatic or aryl ester or half-ester, and acid halide or an ammonium or amine: salt, under such conditions which yield the esters in a highly polymerized form.

Example 2 17.2 parts by weight of 1-amino-2-chloro-4-nitrobenzene are finely powdered and stirred in 30 parts by weight of concentrated hydrochloric acid. The thick, paste is then treated with parts by weight of ice and diazotised at 0-5 C. with a solution of 7 parts by weight of sodium nitrite in 30 parts by volume of water. After filtration, the diazonium salt solution is run at 5-l0 C. into a suspension of 22.7 parts by weight of l-(tetra hydrothiophene- 1 -dioxide- [3 '1 -3 -methyl-pyrazolone- (5) in 100 parts by volume of water. The coupling is completed after a short time even in a stronger acid medium, and the resultant dyestufi can be filtered off.

.. Example 1.

The paste is It is first thoroughly washed with water and then brought into a; finely divided form by grinding with dispersing and wetting agents according to the method described According to the dyeing instruction given in Example 1, there is obtained on fibres of polyethylene terephthalic acid glycol ester a reddish yellow shade of very good fastness to wet processing, subliming and light.

When the diazo components listed in the following table are coupled with l-(tetrahydrothiophene-1-dioxide-[3'])-3-methyl-pyrazolone-(5), dyestufis are obtained which dye polyester fibres in the following shades according to the method given in Example 1:

When the diazo components listed in the following table are coupled with l-(tetrahydrothiophene-l-dioxide-[3'])-3-phcnyl-pyrazolone-(5) (M.P. 220 C.), dyestuffs are obtained which dye aromatic polyester fibres according to the dyeing method given in Example 1 in the following shades:

Example Shade of the N o. Dlazo component dyeing on polyester fibres 18 l-amino-2-ch1or0-4-nltrobenzene reddish yellow. 19 l-amino-Z-nitro-l-ethoxybenzene interlllse reddish ye ow. 20 1amino-4-nitro-2-meth0xy-5-methylbenreddish yellow.

zene.

When 1-(tetrahydrothiophene-l-dioxide- [3'] )pyrazolone-()-carboxylic acid ethyl ester-(3) (M.P. 228 229 C.) is used as coupling component, the diazo components listed in the following table yield dyestufis which dye aromatic polyester fibres according to the dyeing method given in Example 1 in the following shades:

Example Shade of the No. Dlazo component dyeing on polyester fibres 21 1-amlno-2-chloroA-nitrobenzene greenish yellow.

22 1amino-2-nitro-4-ethoxybenzene interilse reddish ye ow. 23 1-amino-2-chloro-4-nitro-5-methoxybenreddish yellow.

zene. 24 G-methyl-Z-W-aminophenyl)-benzth1ayellowishorange.

zo e.

The diazo components listed in the following table are coupled with l (tetrahydrothiophene 1' dioxide- [3])-pyrazolone-(5)-acetic acid ethyl ester-(3) (M.P. 122 C.). Dyestuifs are obtained which according to the dyeing method given in Example 1 may be dyed on polyester fibres in the following shades:

Example Shade of the No. Dlazo component dyeing on polyester fibres 1-amino-2-chloro-4-nitrobenzene yellow.

l-amino-Z-nitro 4-ethoxybenzene intense reddish yellow. 1-am1no-4-mtro-2-methoxy-5-methylbenreddish yellow.

zene.

4 We claim: 1. A monoazo dyestuif corresponding to the formula wherein R stands for a radical selected from the group consisting of the benzene series and 2-benzthiazolyl, R

means a member selected from the group consisting of hydrogen, a lower alkyl, carboxylic acid lower alkyl ester and lower alkylene carboxylic acid lower alkyl ester, R and R being free of sulf onic and carboxylic acid groups.

2. The monoazo dyestufi corresponding to the formula 3. The monoazo dyestutf corresponding to the for- 4. The monoazo dyestufl corresponding to the formula:

5. The monoazo dyestufi corresponding to the for- No references cited. 

1. A MONOAZO DYESTUFF CORRESPONDING TO THE FORMULA 